The standard and most common method of preparing orders of products is manual picking of orders by workers, where the source pallets are located in static racking and employees follow a circuit through the racking and individually pick products from the source pallet and transfer them onto a client pallet. There are a number of variations on this basic method. There are several disadvantages to manual picking which have driven the development of automated systems, such as:                Low productivity;        Difficulty in finding or retaining labor in some markets;        Workplace injuries resulting from the inherently non-ergonomic task of manual picking;        High cost of manual picking errors; breakage and shrinkage;        Poor use of physical space.        
There are on the other hand several key advantages to manual order picking that have to be weighted when considering automation, such as:                Low capital cost (forklifts and racking);        High Reliability;        Easily scalable;        Product flexibility.        
Despite considerable intellectual property in the field and a healthy number of competitors, there is small market penetration for automated case order preparation. The key factors weighed when considering such systems are:                High cost;        Poor reliability due to high complexity;        Poor space utilization.        
Accordingly, there is a need for an improved automated case order sequencing method and system that can meet the cost, reliability and space utilization requirements of the market.